Pitting corrosion of welded joints of austenitic stainless steels studied by using an electrochemical minicell

A pitting corrosion study of welded joints of austenitic stainless steels (AISI 304 and 316L) has been addressed. A specific small-scale electrochemical cell (minicell) has been used. Four different weldment zones have been studied. The electrochemical methods applied were the potentiodynamic anodic polarization test and cyclic potentiodynamic polarization measurements. These techniques showed that the HAZ was the most critical zone for pitting corrosion for both materials. The results were correlated to the microstructural features of the materials. Finally, a comparative study between minicell and lacquer coating techniques has been done. The results show that it is advisable to use the minicell device if reliable results are wanted.